#include<iostream>
using namespace std;

int n, m;
const int N = 1e5 + 10;
typedef long long LL;
LL a[N], f[N];

int main()
{
    cin >> n >> m;
    for (int i = 1;i <= n;i++)
    {
        cin >> a[i];
        f[i] = f[i - 1] + a[i];
    }
    int l, r;
    while (m--)
    {
        cin >> l >> r;
        cout << f[r] - f[l - 1] << endl;
    }

    return 0;
}